Effect of exercise modality during pregnancy on childhood obesity risk - Project Abstract The in-utero environment, including maternal weight gain and exercise habits, can “program” a child towards disease or health after birth and into adulthood. The often-intergenerational cycle of obesity begins with a significant number of women who are overweight or obese (OW/OB) at the time of conception and throughout pregnancy; these women are more likely to give birth to infants who are macrosomic. By age 5, overweight (OW) children already have signs of metabolic syndrome and cardiovascular disease risks (e.g. obesity, hyperlipidemia, hyperglycemia, hyperinsulinemia, and hypertension). While research has demonstrated benefits of both aerobic and resistance exercise for pregnant women as well as decreased adiposity and improved motor/heart function in their infants, no studies have been done to determine which exercise modes are most beneficial for mother and baby when a woman is overweight or obese at the time of conception. For adults in general, combined aerobic and resistance exercise (AERE) delivers the greatest metabolic improvements (e.g. increased insulin sensitivity, improved heart function, decreased adiposity). Therefore, the purpose of this study is to identify which prenatal exercise type(s) will elicit the greatest positive impact on maternal and infant health while reducing metabolic risk markers in OW/OB pregnant women relative to non-exercising counterparts. Using a randomized design, 284 pregnant women will undergo an exercise intervention (AE, RE, AERE) from enrollment (~13-16 weeks gestation) until delivery (~40 weeks gestation). The central hypothesis of this study is that adding RE improves outcomes; thus, the COMBINATION of aerobic and resistance exercise not only will improve infant cardiometabolic health outcomes, as compared to AE alone, but will have the best compliance of all groups. We will test this hypothesis with two specific aims to: (1) Determine the influence of different exercise modes during OW/OB pregnancy on infant cardiometabolic health and growth trajectories; and (2) Determine the most effective exercise mode in OW/OB pregnancy on improving maternal cardiometabolic health. Methods will include measurements such as weight, abdominal circumference, blood pressure, lipids, and other biomarkers for both mothers and infants. The study will also track maternal and infant cardiometabolic outcomes through the post-partum period, up to 12 months. This work has the potential to impact clinical practice by revealing the earliest and most effective intervention to reduce the intergenerational cycle of metabolic dysfunction, including obesity, in women and children. .